Interfacial composition, structure, and properties of ionic liquids and conductive polymers for the construction of chemical sensors and biosensors: a perspective

Abstract

The fields of chemical and biosensors have grown tremendously from the improvements in the transducer and readout components, as well as in sensing materials and interface designs to meet the always rising standards for accuracy, cost, portability, and accessibility in a broad range of sensing applications. Although the transducer and readout components can often be interchangeable for a specific target analyte, the receptor element of the sensor device, which is the ‘sensing material with its interface chemistry,’ must be specifically tailored to any sensing mechanism. The interfacial properties of the sensing components play essential roles in determining the analytical performance and the overall cost of the sensor technology in both technical and commercial senses. Ionic liquids (IL) are liquids often composed of bulky organic cations or anions, whereas conductive polymers (CPs) are solids with dopant ions in a rigid organic framework. Both ILs and CPs have been demonstrated as promising smart/tunable and low-cost materials for chemical and biosensor development. In this article, we present our opinion discussing the unique features of using ILs and CPs as molecular building blocks to design robust and functional sensing interfaces for next-generation, low-cost, and miniaturized electrochemical sensor development.